One way that a wireless cellular service provider can improve the coverage provided by a base station or group of base stations is by using a distributed antenna system (DAS). A DAS typically comprises one or more master units and one or more remote units that are communicatively coupled to the master units. One type of DAS is an analog DAS, in which DAS traffic is distributed between the master units and the remote units in analog form. Another type of DAS is a digital DAS, in which DAS traffic is distributed between the master units and the remote units in digital form.
Remote units in a DAS are communicatively coupled to a master unit via a communication link. Some of the devices in the remote units are reconfigurable and require upgrades to firmware from time to time. The upgrades affect how the remote unit can meet requirements such as bug fixing, feature addition, feature enhancement, mode switching (for example, low power mode), etc. One such device is the physical layer (PHY) device in a remote unit that includes firmware that implements the protocol or algorithm for the PHY device to establish and maintain the communication link between the remote unit and the master unit. Typically, the firmware for the PHY device in a remote unit is upgraded by a technician physically proximate the remote unit via a management port. The technician establishes a direct link via the management port to upgrade the firmware and the communication link is disabled during the upgrade process. The direct communication link via the management port is distinct from the communication link between the remote unit and the master unit.
It is common for the remote units of a DAS to be positioned in locations that are inconvenient for physical access. For example, a remote unit may be positioned in the rafters of a professional sports stadium. Such locations require special equipment to physically access the remote unit and increase the time and cost of maintenance of the remote units. If numerous upgrades are required for the PHY device or other reconfigurable devices that must retain compatibility with the PHY device, it becomes impractical to perform the upgrades locally with a technician.